io_uring_sqe_set_data(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO | COLOPHON

io_uring_sqe_set_data(3)     liburing Manual     io_uring_sqe_set_data(3)

NAME         top

       io_uring_sqe_set_data - set user data for submission queue event

SYNOPSIS         top

       #include <liburing.h>

       void io_uring_sqe_set_data(struct io_uring_sqe *sqe,
                                  void *user_data);

       void io_uring_sqe_set_data64(struct io_uring_sqe *sqe,
                                    __u64 data);

DESCRIPTION         top

       The io_uring_sqe_set_data(3) function stores a user_data pointer
       with the submission queue entry sqe.

       The io_uring_sqe_set_data64(3) function stores a 64-bit data value
       with the submission queue entry sqe.

       After the caller has requested a submission queue entry (SQE) with
       io_uring_get_sqe(3), they can associate a data pointer or value
       with the SQE. Once the completion arrives, the function
       io_uring_cqe_get_data(3) or io_uring_cqe_get_data64(3) can be
       called to retrieve the data pointer or value associated with the
       submitted request.

       Note that if neither of these functions are called, or the
       user_data field in the sqe isn't set manually either, then the
       field may contain a value from a previous use of this sqe. If an
       application relies on always having a valid user_data value
       present, it must always assign one to each sqe.

RETURN VALUE         top

       None

SEE ALSO         top

       io_uring_get_sqe(3), io_uring_cqe_get_data(3)

COLOPHON         top

       This page is part of the liburing (A library for io_uring)
       project.  Information about the project can be found at 
       ⟨https://github.com/axboe/liburing⟩.  If you have a bug report for
       this manual page, send it to io-uring@vger.kernel.org.  This page
       was obtained from the project's upstream Git repository
       ⟨https://github.com/axboe/liburing⟩ on 2025-02-02.  (At that time,
       the date of the most recent commit that was found in the
       repository was 2025-01-22.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there is
       a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

liburing-2.1                November 15, 2021    io_uring_sqe_set_data(3)

Pages that refer to this page: io_uring_cqe_get_data(3)io_uring_cqe_get_data64(3)io_uring_get_sqe(3)io_uring_sqe_set_data(3)io_uring_sqe_set_data64(3)